Composition for colored smoke dissemination

ABSTRACT

Disclosed is a composition for the pyrotechnic dissemination of colored smoke. The composition contains an oxidizer, a material which produces a colored smoke cloud when heated and a binder fuel. The binder fuel is the copolymerization product of a polyaziridinyl compound and a polyfunctional amine or mercaptan terminated curing agent.

United States Patent m1 Jankowiak et al.

I45] eb. 20, 1973 1 COMPOSITION FOR COLORED SMOKE DISSEMINATION [75]Inventors: Erwin M. Jankowiak, Sanford; Earl Thomas Niles, Midland; bothof Mich.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

[22] Filed: Nov. 12, 1970 [21] Appl. No.: 89,132

[52] US. Cl ..l49/l9, 149/84 [51] Int. Cl. ..C06b 3/00, C06b 5/06 [58]Field of Search ..l49/19, 20, 84

[56] References Cited UNITED STATES PATENTS 3,147,161 9/1964 Abere eta]. ..149/84 X 3,586,552 6/1971 POMS at al ..149/l9 PrimaryExaminer-Benjamin R. Padgett Attorney-Griswold & Burdick, Jerome L.Jeffers and William R. Norris [57] 4 ABSTRACT 10 Claims, No DrawingsCOMPOSITION FOR COLORED SMOKE DISSEMINATION BACKGROUND OF THE INVENTIONCompositions for the dissemination of colored smoke serve as daytimesignaling devices for both military and civilian use. Such compositionshave been prepared by pressing an oxidizer, color emitter and organicbinder at high pressures to form a coherent composition which uponignition emits a cloud of colored smoke. This method has thedisadvantage of requiring the dangerous high pressure treatment ofunstable materials and restricts the size and shape of the grains whichare prepared. A castable composition, i.e. one that can be poured into amold and allowed to harden into a solid grain is desirable. In such asystem, a castable mixture is prepared by combining an oxidizer, liquidresin-curing agent combination and colored smoke producing composition,i.e. dye, which is poured into a mold and cured. A problem arises in theuse of many resin based binder systems due to the fact that they burn attemperatures which are sufficiently high to pyrolize the more heatsensitive dyes rather than disseminate them.

It is an object of the present invention to provide a novel compositionfor the dissemination of colored smoke.

An additional object is to provide such a composition which may beprepared by pour casting with curing at moderately elevatedtemperatures.

An additional object is to provide such a composition which burns at atemperature sufficiently low to avoid pyrolysis of heat sensitive dyes.

The present invention is a polymer-bonded pyrotechnic formulation forcolored smoke dissemination which comprises an oxidizer, a polymericbinder and a dye. The oxidizer, which makes up from about 16 to 40 percent of the composition, is a particulate alkali metal or ammoniumnitrate, chlorate or perchlorate. The binder, which comprises from about15 to 32 per cent of the composition, is the copolymerization product ofa polyaziridinyl compound and a polyfunctional amine or mercaptanterminated curing agent. The polyaziridinyl compound is selected fromthe group of:

Tris [2-(1-aziridinyl) ethyl] trimesate Tris [2-(l--aziridinyl) ethyl]trimellitate Bis [2-(1-aziridinyl) ethyl] terephthalate Bis[2-(l-'aziridiny1) ethyl] phthalate or Bis [2-(1-'aziridiny1) ethyl]isophthalate. The curing agent is selected from the group ofethylenediamine, diethylenetriamine, triethylenetetramine,tetraethylenepentamine,

Particle size of the dye if not critical to operability of theinvention. In general, particles ranging in size from 15 y. to 2000 p.in their longest dimensions are preferred. Multi-modal size distributionof the particles is desirable for optimum packing properties. Theparticle size distribution necessary for the preparation of a castablecomposition will vary with the dye composition employed. This sizedistribution is readily determined by routine experimentation.

The oxidizer particles should range in size from 15 [L to 300 [L intheir longest dimension with a particle size range of from 20 p. to 250p. being preferred.

Premixing of the proper size oxidizer and dye particles and subsequentblending of the mixture with the liquid binder components providesacomposition which can be pour cast into the desired configuration andcured into a coherent grainlike munition. The munition is readilyignited by conventional means to produce a colored smoke cloud.

The invention is further illustrated by the following examples in whichall percentages are by weight, as are all percentages and ratiosdisclosed herein.

EXAMPLE 1:

A composition for the dissemination of green smoke was prepared by drymixing 40 percent of a fine particle size green dye and 32 percentparticulate KC10 The green dye consisted of a mixture of 70.1 percentSolvent Green 111, 20.9 percent Benzanthrone and 9.0 percent Vat YellowIV. The individual dyes are described more fully in MilitarySpecifications (hereafter Mil-Spec) D 3277A, D50074B and D50029Brespectively. The KC10 is described in Mil- Spec P-150B. To thedye/oxidizer combination was added 24.2 percent Tris [2-(l-aziridinyl)ethyl] trimellitate and 3.8 percent triethylenetetramine (TETA). Thecomposition, which was only marginally castable, was cured to a hardtough grain by heating at C. for approximately 1 hour. A set of 23 gm.munitions having the above composition was placed in surveillance. TableI sets out the performance and surveillance data of the formulation.

TABLE I Surveillance and Performance Data on Formulation Prepared inExample I Vaporization eff. amt. of aerosolized dye/amt. of dye informulation Yield amt. of aerosolized dye/total wt. of formulation Thegreen dye consisted of two yellow dyes and one blue one. When munitionscontaining this mixture are functioned, gradations of smoke color areproduced depending upon the combustion characteristics of theformulation. A color index, which is determined by spectrophotometricmeasurements, of unity would indicate that the green dye components weredisseminated in the same ratio as they occur in the original green dye.It has been discovered that a composition having a color index of about12 appears more truly green than those having a color index of unity.

EXAMPLE 11:

A formulation was prepared as in Example I by blending 45 percent of thegranular green dye, 27.5 percent KC 22 percent Tris [2-(l-aziridinyl)ethyl] trimellitate and 5.5 percent TETA. The composition, which waspour castable, was cured at 70 C. for approximately 2 hours. Uponignition the formulation was found to have the following properties:

Table 11 Burning rate, in./sec. 0.07 Combustion time, sec./23gm. 12Cloud Color dense dark green Cloud Density Dense vaporizationEfficiency, 88 Smoke Yield, 40 Color Index 1.08

Example 111:

A formulation for the dissemination of yellow smoke was prepared byblending a particulate yellow dye of composition Vat Yellow IV (35.7percent) and Benzanthrone (64.3 percent) in an amount equal to 40percent of the formulation. The remainder of the formulation consistedof 32 percent KC10 24.2 percent Tris [2-(l-aziridinyl) ethyl]trimellitate and 3.8 percent TETA. A formulation for disseminating whitesmoke was prepared as above except that a granular white dye2-chloro-anthraquinone was employed. A munition for dissemination of redsmoke was prepared with 50 percent particulate1-methylaminoanthraquinone dye, 24.9 percent KClO 21.9 percenttrimellitate and 3.2 percent TETA. Performance and 12-week surveillancedata for these formulations are given in Tables 111, IV and V.

Performance and Surveillance Data White Dye Performance 12 weeksParameter Original at 72 C.

Weight of grain, gm. 23 23 Burning rate, in./scc. 0.034 0.030 Combustiontime, sec./23gm. 22 28 vaporization eff, k 93 91 Smoke yield, 37 36Color Good Good Table V Performance and Surveillance Data Red DyePerformance 12 weeks Parameter Original at 72 C.

Weight of grain, gm. 23 23 Burning rate, in./sec. 0.024 0.026 Combustiontime, sec./23gm. 36 33 vaporization eff, 87 87 Smoke yield, 44 44 ColorGood Good EXAMPLE IV;

In a manner similar to that of the previous examples a composition fordissemination of violet smoke was prepared from the followingcomponents:

Component Wt. of Composition Binder 22.5% trimellitate) (20% TETA)Oxidizer 27.5% (KCIO Dye 50% The dye employed corresponded to Mil-SpecD3691 A which is a mixture of 81.5% 1,4-diamino-2, 3-dihydroanthraquinonc (Mil- Spec D3668A) and 18.5% lmethylaminoanthraquinone (Mil-Spec D3284A).

Additional dyes that may be used in the present invention include:

Orange:

1. l-Benzoazo-Z-napthol 2. 4,5-Dibromo-3,6-fluorandial 3. 1,2-Dihydroxyantraquinone 4. l-0-Tolylazo-2-napthol Yellow:

1. 1,2 Benzpyrene 2. 4-Dimethylaminoazobenzene 3.9-Diethylamino-7-phenyl-S-benzophenazinone 4.2-(4-Dimethylaminoazophenyl) naphthalene Others:

1. l-Hydroxy-4 paratho1uidinoanthraquinone (violet) 2.l,4-Di-p-toluidinoanthraquinone (green) 3. 2, 4, 5,7-tetrabromo-3,fi-fluorandiol (red) 4. l-Xy1ylazo-2-naphthol (red) WECLAIM:

l. A polymer-bonded, pyrotechnic formulation for colored smokedissemination which comprises:

a. from about 16 to 40 percent of a particulate nitrate, chlorate orperchlorate of an alkali metal or ammonium as oxidizer;

b. from about 15 to 32 percent of the copolymerization product of apolyaziridinyl compound selected from the group of:

Tris [2-( l -aziridinyl) ethyl] trimesate,

Tris [2-(l-aziridiny1) ethyl] trimellitate,

Bis [2-(l-aziridinyl) ethyl] terephthalate,

Bis [2-(l-aziridinyl) ethyl] phthalate or Bis [2-( l -aziridinyl) ethyl]isophthalate and a polyfunctional amine or mercaptan terminated curingagent selected from the group consisting of ethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,pentaethylenehexamine, 1,2-bis (thioethylamino) propane and ethylenemercaptan as binder, and

c. the balance of a particulate dye for the pyrotechnic dissemination ofcolored smoke.

2. The formulation of claim 1 which is made up of 24 to 32 percentoxidizer, 22 to 30 percent binder and the balance of the dye to bedisseminated.

3. The formulation of claim 1 wherein the ratio of polyaziridinylcompound to curing agent is from 4:1 to 6:1.

4. The formulation of claim 3 wherein the binder is made up of thecopolymerization product of Tris [2-(1- aziridinyl) ethyl] trimellitateand triethylenetetramine.

5. The formulation of claim 4 wherein the dye is a mixture of SolventGreen III, Benzanthrone and Vat Yellow IV.

6. The formulation of claim 4 wherein the dye is l-

1. A polymer-bonded, pyrotechnic formulation for colored smokedissemination which comprises: a. from about 16 to 40 percent of aparticulate nitrate, chlorate or perchlorate of an alkali metal orammonium as oxidizer; b. from about 15 to 32 percent of thecopolymerization product of a polyaziridinyl compound selected from thegroup of: Tris (2-(1-aziridinyl) ethyl) trimesate, Tris(2-(1-aziridinyl) ethyl) trimellitate, Bis (2-(1-aziridinyl) ethyl)terephthalate, Bis (2-(1-aziridinyl) ethyl) phthalate or Bis(2-(1-aziridinyl) ethyl) isophthalate and a polyfunctional amine ormercaptan terminated curing agent selected from the group consisting ofethylenediamine, diethylenetriamine, triethylenetetramine,tetraethylenepentamine, pentaethylenehexamine, 1,2-bis (thioethylamino)propane and ethylene mercaptan as binder, and c. the balance of aparticulate dye for the pyrotechnic dissemination of colored smoke. 2.The formulation of claim 1 which is made up of 24 to 32 percentoxidizer, 22 to 30 percent binder and the balance of the dye to bedisseminated.
 3. The formulation of claim 1 wherein the ratio ofpolyaziridinyl compound to curing agent is from 4:1 to 6:1.
 4. Theformulation of claim 3 wherein the binder is made up of thecopolymerization product of Tris (2-(1-aziridinyl) ethyl) trimellitateand triethylenetetramine.
 5. The formulation of claim 4 wherein the dyeis a mixture of Solvent Green III, Benzanthrone and Vat Yellow IV. 6.The formulation of claim 4 wherein the dye is1-methylaminoanthraquinone.
 7. The formulation of claim 1 wherein theparticle size of the dye is within the range of from 15 Mu to 2,000 Muin the longest dimension.
 8. The formulation of claim 1 wherein theparticle size of the oxidizer is from 20 Mu to 250 Mu .
 9. Theformulation of claim 1 wherein the dye is a mixture of Vat Yellow IV andbenzanthrone or 2-chloro-anthraquinone.